Noise from engine bay during startup

[tahirawan11]

Hi,

I have a Toyota Aygo (AB10_KGB10_2008). When I start the car; for the first few minutes there is a high-pitch noise from the engine bay. The noise goes away once the car is run after a couple of minutes. But it may come again occasionally within the first 10 minutes of the drive. But once the car is run for 10 minutes or more then the noise does not return.  I have attached a video. Can someone help me to identify the component the noise is coming from ? I think it could be the Oil pump or the AC compressor. The Alternator was changed less than a year ago and the Water pump was replaced two years ago so I think the noise should not come from there? I have a mechanic stethoscope but no experience in using it. So if someone can give me any ideas on how i I can use it to pinpoint the sources of the noise.

 

Thanks

[Vandals01]

Very unlikely to be the oil pump, because that's driven by the crankshaft as part of the timing cover.

It could be the belt that drives the Alternator / water pump & AC compressor.  When it slips, it will makes squeaking sound.  To verify, get a spray bottle filled with tap water, spray it onto the belt when the car is running.  If the noise comes back soon the belt touches water, it means the belt is slipping. 

For the stethoscope, you just tap on the various components and see which one makes the loudest squeaking sound.  Say if you want to test the Alternator, you would tap the stethoscope on A.

To the bottom of the Alternator, that's the AC compressor, find a solid part that's not spinning and tap on it.

[tahirawan11]

Hi Vince,

 

Many thanks for your reply, I will do the test to verify if it is the belt which is slipping. The belt was changed last summer and at that time there were no issues, I have noticed this issue came when the winter weather has started. 

 

If it is the belt which is slipping how can I tight it / fix it ?

 

thanks in advance

[Stecha]

I cant open your file for some reason

Anyway, does your noise sound similar to this post ?

 

[tahirawan11]

Hi everyone,

Now i have tested the belt with some water spray and I soon I sprayed the noise became worse so it confirm that the noise is coming from the belt. I found a tutorial on youtube on fighting the belt. Now i have drive the car for a couple of days and the noise is gone 🙂 So thanks everyone for your help and support